FAST pack for yf-19

[Mr March]

I'm gonna re-watch and see how the long-range missiles pop out of the leg.

I always thought they popped from underneath the Lep FPs but it's been a long time since i watched.

I can't understand you saying that they aren't/not useful for extra armor (along the legs) though...

I’m not sure if I can concretely say whether those two missiles from the YF-19 were launched from the Internal Engine/Leg palette or FAST Pack by just looking at the animation frame by frame. One frame they are not there and then suddenly they appear already outside the craft. No tell tale signs are given to indicate where they came from.

I will say this however, the FAST Packs on the YF-19 do not need to lift or open to fire their missile ordnance. They have several launching ports on the exterior. However, the internal leg palettes could likely not launch anything but micro missiles through the FAST Packs (since the FAST packs only carry micro-missiles), so larger ordnance would require the FAST Packs to lift so that the YF-19 internal palettes could launch the larger missiles. Makes sense I think.

I’m sure the FAST Pack sets are not any less vulnerable than the regular valkyrie armor, but I don’t see how they offer any significant protection. As a target being fired upon, the Valkyrie is still largely uncovered by the FAST Packs. This holds true in all modes, with the possible exception of a direct rear attack upon the battroid mode. In fact, FAST Packs like those of the VF-1 and VF-11 make the Valkyrie a larger target. I really doubt they serve as any significant protection. At least, I'm not aware of any specific mention of protection.

Edited July 23, 2007 by Mr March

[sketchley]

Just glancing at it, it looks like the list is pretty much correct.

Some notes:

the VF-11D Kai and VF-22 Transatmospheric Super Parts are the same, and they are also used in Sound Energy/Spiritia Warfare.

the transatmospheric and atmospheric packs/parts contain (if I remember the translation correctly) a scram jet engine.

[Skull-1]

Perhaps it's better to think of them as gas tanks. There is armour on them, but it is to prevent the gas within the tank from exploding when the VF is hit. Would you use a gas tank as a shield?

I disagree here.

There is no requirement for them to contain FUEL, only reaction mass. This could be water or anything else you can think of that can be expelled.

I define them as FAAST Packs. Fuel Armor Armament System Tactical.

Though fuel is somewhat a misnomer.

Edited July 23, 2007 by Skull-1

[sketchley]

I disagree here.

There is no requirement for them to contain FUEL, only reaction mass. This could be water or anything else you can think of that can be expelled.

I define them as FAAST Packs. Fuel Armor Armament System Tactical.

Though fuel is somewhat a misnomer.

Then please explain why:

a) they explode violently when damaged

and

b) why all publications that refer to them as such, use the term FAST, even in Japanese? (You can spot the acronym buried in Japanese text, as roman letters are used.) Eg: "TIA Special: Macross Plus", Pg. 58.

[Dante74]

Then please explain why:

a) they explode violently when damagedand

b) why all publications that refer to them as such, use the term FAST, even in Japanese? (You can spot the acronym buried in Japanese text, as roman letters are used.) Eg: "TIA Special: Macross Plus", Pg. 58.

I can answer that first one:

Because it's a cartoon and water seeping out of a bullet hole wouldn't be very spectacular.

Can't argue with point b) though.

[eugimon]

I can answer that first one:

Because it's a cartoon and water seeping out of a bullet hole wouldn't be very spectacular.

Can't argue with point b) though.

[sketchley]

Hardy har har.

A more technical explanation is warranted, please and thank you; because the technical jargon removed, common internet English using explanation has caused the confusion.

Technical jargon full explanation: FAST Packs are filled with reactant. Reactant being used both as fuel for the thermonuclear engines of a VF's engine nacelles, as well as being used, whilst in an atmosphere-less environ as the substance used to move through the engine to provide thrust.

[eugimon]

Since we know really nothing about the operation of the "thermonuclear" engines in a valk, it's pretty much useless to conjecture about what the fuel source would be. If it's a fusion reactor based on real-world technology, the fast packs would just be carrying, essentially, water. Shooting them, or rupturing them, may cause an explosion of water, as the tanks maybe kept under pressure in order to hold more fuel for the engines.

Or, the thermonuclear engines maybe of some sort of super efficiency and not require an additional fuel source, in which case the FAST pack may contain some sort of combustible liquid that is injected into the heat output of the fusion reactor to provide thrust, which could explain why FAST packs go boom.

Or, the explosions could be due to the type of munition used, or they could be due to the warheads in the micro missiles exploding.

Or, as Dante pointed it, it's a cartoon. And like cars in movies, these things just blow up for no particular reason.

[sketchley]

http://www.google.co.jp/search?hl=ja&q...macross&lr=

[eugimon]

Tell us what you expect us to look at Sketch, pointing us to a google search, whose first hit is to point us back at us is hardly helpful.

If you're referring to the posts @ macrossRPG.com, that's all speculation as well. They don't know anything more than us. Though apeman007 feels the same way I do, that "thermonuclear" in the macross universe has little or nothing to do with a real-world fusion engine after which its named.

[Mr March]

I agree that most often explosions are utilized in action sequences because they are dramatic, even if unrealistic. I would think dramatic effect is most likely the reason for exploding FAST Packs in Macross Plus.

But just as a note, wouldn't it be possible for FAST Packs to explode, even were it to be filled with water as a reactant? If the FAST Pack (and the reactant inside) were penetrated by something sufficiently hot (say, a laser or other beam weapon) the hydrogen in the water could very well ignite and cause an explosion, yes?. The temperatures have to be very hot (a thousand or more degrees if I understand correctly) but I thought this may be a plausible explanation, if we go with the water assumption anyway (a very big "if")

[sketchley]

Tell us what you expect us to look at Sketch, pointing us to a google search, whose first hit is to point us back at us is hardly helpful.

If you're referring to the posts @ macrossRPG.com, that's all speculation as well. They don't know anything more than us. Though apeman007 feels the same way I do, that "thermonuclear" in the macross universe has little or nothing to do with a real-world fusion engine after which its named.

You point out the obvious (Macross is a work of fiction), I point out the obvious. Quid pro quo.

The names Sketchley, and it's to show that not only some of us, but the majority of us have been down these lines of thought before. Apeman007, FYI, is me. :wave:

[eugimon]

You point out the obvious (Macross is a work of fiction), I point out the obvious. Quid pro quo.

The names Sketchley, and it's to show that not only some of us, but the majority of us have been down these lines of thought before. Apeman007, FYI, is me. :wave:

I pointed out the obvious because you were demanding a technical answer to what is obviously a dramatic effect, sketch.

AND before I agreed with Dante, I gave multiple theories on why the FAST packs would explode when hit, which you completely ignored and came back with some obtuse, condescending link post. So no, it's not quid pro quo at all.

I further find it odd and sad that 3 years ago you recognized that the technology and its effects were completely made up, and now, you're on some sort of pedantic which hunt for answers, no one can give because they don't exist. And yeah, we have had this discussion before. On this board even. In the end, kawamori and company don't describe their technology because it's fanciful and made up. They don't tell us what the fuel is, they don't tell us what they mean by a thermonuclear reactor, it's pretty obvious that they're not talking about any sort of fusion reactor. In the end, it's a work of fiction, it's a mystery technology that only shares a real world name, and nothing more.

Edited July 24, 2007 by eugimon

[Vic Mancini]

I can answer that first one:

Because it's a cartoon and water seeping out of a bullet hole wouldn't be very spectacular.

I tend to agree here. It's the same reason why we hear the sounds of lasers and explosions in virtually all fictional space combat scenes, (Macross, Star Wars, BSG, etc). It's dramatic effect and entertainment more than rational science. Explosions simply look and sound cool.

I think the purpose of FAST packs themselves sometimes falls under the same category. Besides housing more verniers and firepower, I doubt they have much practical use besides looking cool. They made sense on a VF-1, but I think they are more of a novelty and a Macross tradition on other Valkyries.

[Zinjo]

Macross have demanded that specific non-literal translations be used, despite the requested word having little or nothing to do with the original Japanese (Supervision Army vs. Inspection Army.) I am most leery of this last one, as non-native speakers of English don't tend to have the same understanding of English. (Everyone knows of the Bubble Economy, right? One Japanese economist recently tried to coin the term Froth Economy. Froth being many little bubbles. However, I understand the word as meaning more than gas contained within a membrane. Think dog frothing at the mouth.)

Well as we know, the parts of communication are expression and understanding.

It is entirely possible that the creators have a different understanding of what "Supervision" means as compared to the general English speaking world. It may be inaccurate as you understand it, but they adamantly believe that the term, as they understand it, best fits with the Japanese term as they understand that.

As you've already noted with the "Bubble Economy" analogy, this is one of the issues with language translation..

[Mr March]

I think the purpose of FAST packs themselves sometimes falls under the same category. Besides housing more verniers and firepower, I doubt they have much practical use besides looking cool. They made sense on a VF-1, but I think they are more of a novelty and a Macross tradition on other Valkyries.

You're very likely on to something here. I think that in the case of SDF Macross, the FAST Packs helped to sell the VF-1 as an all-environment fighter. The VF-1 looks much more like a science fiction fighter all decked out in the "Super" variant for space flight and much less like an "F-14 in space."

[Knight26]

If we want to be realisitic then the most likely candidate for the fuel source contained in the FAST Packs would probably be some form of liquid hydrogen. This would allow for some very nice reaction mass and if the FAST pack, or any fuel tank, was breached by a sufficiently energetic weapon then it would probably undergo an immediate state change. Going from a cryogenic liquid to a vapor gas in an instant would be quite the violent reaction and would mimic an explosion, if not cause one in the presence of enough oxygen. In terms of what we see on screen in SDF, DYRL, Plus, and 7 this makes sense. The explosions we typically see in space occur as short lived spheres of light, basically the reactor goes critical due to a hit and violently burns off the last of hydrogen, in essence forming a miniature short lived star, a tiny supernova baby. In plus when we see fast packs get hit and ejected there is an immediate explosion that follows. This also corelates nicely. The fuel tank ruptures and starts to vent violently, the breach is then sufficiently hot enough and the pressure difference high enough to force a violent state change in the liquid H2 that results in an explosion in the oxygenated environment.

As for how the thermonuclear engines operate i think that has already been touched on sufficiently. BUt basically you have a fusion reaction burning in each one, which requires some fuel, in this case probably H2, convinient eh? In atmo the compressors and turbines work just like a jet engine, drawing in outside air, compressing it and then funneling it into the combustion chamber, but instead of jet fuel being added the compressed air passed over the reaction furnace. This superheats the air resulting in a state change that ignites the oxygen and hydrogen before forcing it out the back for thrust. In space with the absence of air the same fuel that fires the reaction furnace is directly piped into the combustion chamber and flash ignited, this also has the added benefit of still turning the turbines to produce power, in case the reaction furnace doesn't produce enough already. This does however result in the fuel being much more rapidly consumed and mandates the use of external fuel tanks, or FAST packs for extended operations. Afterburner would still act in much the same way as a conventional jet engine by simply forcing the liquid H2 fuel into the afterburner can where it would be flash ignited by the already superheated gasses.

[Vic Mancini]

You're very likely on to something here. I think that in the case of SDF Macross, the FAST Packs helped to sell the VF-1 as an all-environment fighter. The VF-1 looks much more like a science fiction fighter all decked out in the "Super" variant for space flight and much less like an "F-14 in space."

Exactly. And like I said, I think the VF-1 FAST packs make the most sense in practical terms. To me a VF-1 looks the most like what a regular atmospheric fighter jet would look like if Nasa and the military worked together to make it space faring.

But ever since the VF-1 I think the FAST packs have been more of a novelty than anything. The kid inside us says, "what good is a Valkyrie if it can't be supe'd up with extra armor?", even if that armor's performance enhancing nature is a mystery. FAST packs have become a Macross tradition and will likely continue to be designed for Valks that don't necessarily need them. They hold extra missiles, and mostly look cool, and that's why they're there. Much like how explosions in space sound cool and that's why we hear them even though space is a vacuum.

And in Macross Plus we saw how they make good explosive eye candy when they become parts that can be damaged and jettisoned into a fiery eruption without damaging the actual Valk. Maybe the 19 and 21's FAST packs were designed from the get-go to be parts that Isamu and Guld could destroy in battle without crippling each other's Valks and wrecking a good fight scene.

[Dante74]

Exactly. And like I said, I think the VF-1 FAST packs make the most sense in practical terms. To me a VF-1 looks the most like what a regular atmospheric fighter jet would look like if Nasa and the military worked together to make it space faring.

But ever since the VF-1 I think the FAST packs have been more of a novelty than anything. The kid inside us says, "what good is a Valkyrie if it can't be supe'd up with extra armor?", even if that armor's performance enhancing nature is a mystery. FAST packs have become a Macross tradition and will likely continue to be designed for Valks that don't necessarily need them. They hold extra missiles, and mostly look cool, and that's why they're there. Much like how explosions in space sound cool and that's why we hear them even though space is a vacuum.

And in Macross Plus we saw how they make good explosive eye candy when they become parts that can be damaged and jettisoned into a fiery eruption without damaging the actual Valk. Maybe the 19 and 21's FAST packs were designed from the get-go to be parts that Isamu and Guld could destroy in battle without crippling each other's Valks and wrecking a good fight scene.

Thank Gawd! finally someone that feels the same way about FAST packs on Valks other than the VF-1. I started a thread about this subject a couple of months ago, but it left me feeling seriously misunderstood by my fellow MW members. poor little old meee!

[eugimon]

If we want to be realisitic then the most likely candidate for the fuel source contained in the FAST Packs would probably be some form of liquid hydrogen. This would allow for some very nice reaction mass and if the FAST pack, or any fuel tank, was breached by a sufficiently energetic weapon then it would probably undergo an immediate state change. Going from a cryogenic liquid to a vapor gas in an instant would be quite the violent reaction and would mimic an explosion, if not cause one in the presence of enough oxygen. In terms of what we see on screen in SDF, DYRL, Plus, and 7 this makes sense. The explosions we typically see in space occur as short lived spheres of light, basically the reactor goes critical due to a hit and violently burns off the last of hydrogen, in essence forming a miniature short lived star, a tiny supernova baby. In plus when we see fast packs get hit and ejected there is an immediate explosion that follows. This also corelates nicely. The fuel tank ruptures and starts to vent violently, the breach is then sufficiently hot enough and the pressure difference high enough to force a violent state change in the liquid H2 that results in an explosion in the oxygenated environment.

As for how the thermonuclear engines operate i think that has already been touched on sufficiently. BUt basically you have a fusion reaction burning in each one, which requires some fuel, in this case probably H2, convinient eh? In atmo the compressors and turbines work just like a jet engine, drawing in outside air, compressing it and then funneling it into the combustion chamber, but instead of jet fuel being added the compressed air passed over the reaction furnace. This superheats the air resulting in a state change that ignites the oxygen and hydrogen before forcing it out the back for thrust. In space with the absence of air the same fuel that fires the reaction furnace is directly piped into the combustion chamber and flash ignited, this also has the added benefit of still turning the turbines to produce power, in case the reaction furnace doesn't produce enough already. This does however result in the fuel being much more rapidly consumed and mandates the use of external fuel tanks, or FAST packs for extended operations. Afterburner would still act in much the same way as a conventional jet engine by simply forcing the liquid H2 fuel into the afterburner can where it would be flash ignited by the already superheated gasses.

I doubt the eninges on a valk burn hydrogen, much more likely they burn helium 3 which would allow for a far smaller eninge (less shielding) and would therefor contribute less mass to the valk, allowing for a better weight/thrust ratio. Helium 3 would also be easier to mine and easier to work with. But even if pressurized hydrogen was used, hydrogen, is such a light gas, that even if the tanks were catastrophically ruptured, the gas would burn up and cool, away from the valk. Hydrogen fires don't even get hot enough to melt glass. And they wouldn't produce the orange explosions depicted in macross, they would be a much cooler blue flame.

The real problem with claiming a fusion based engine is just the size necessary and the constraint of the size and space of the leg. If we're talking about a hydrogen fusion reactor, you'll need some pretty extensive shielding to protect the people around the eninges from radiation. Real world fusion reactors have a meter's worth of shielding around them. Even if the engine were a helium fusion engine, the reactor would still be the size of a basketball.

Then there's just the reality of having superheated plasma, at 100 million K, floating in a magentically levitated ring, in the what is aruguably, the part of the mech that will receive the most amount of shock and stress. I'm sorry, but even with magically OT, this is just preposterous. I find it just as far fetched as singing inducing vegetation growth and mineral levitation.

I still maintain, mystery technology, real world name. Nothing in common other than the name.

Edited July 24, 2007 by eugimon

[Zinjo]

If the tanks were filled with pure oxygen (why I don't know?) that would produce a spectacular explosion.

[Mr March]

But ever since the VF-1 I think the FAST packs have been more of a novelty than anything. The kid inside us says, "what good is a Valkyrie if it can't be supe'd up with extra armor?", even if that armor's performance enhancing nature is a mystery. FAST packs have become a Macross tradition and will likely continue to be designed for Valks that don't necessarily need them.

As much as style and that ever present "cool" factor may be a part of Macross, I would stop short of calling FAST Packs needless. Space is huge, more so than most people can grasp. Interplanetary distances within the Sol system alone are vast. Even utilizing the magic of OverTechnology and the remarkable power/efficiency it has granted vehicles in the Macross universe, the distances variable fighters must travel almost demands specialized fuel equipment. Particularly in the Macross Plus/Macross 7 era, variable fighters are increasingly independent and can be seen in operation without carriers at all. The Fold Booster is yet another range extension technology. If anything, FAST Packs would remain relevant as the UNS continues to deploy further and faster with each new variable fighter generation.

[eugimon]

If the tanks were filled with pure oxygen (why I don't know?) that would produce a spectacular explosion.

Well, let's say the valk's power plant WAS a hydrogen fusion engine. The easiest way to get the deuterium and possibly tritium for the reaction engine would be to process water, so you would have large amounts of oxygen left over. The oxygen could be compressed into a liquid form and used as the reactant in the FAST packs. And yeah, it would make nice booms.

But for reasons I've stated in my previous post, I don't think thermonuclear engines in a valk are hydrogen fusion reactors.. they're just too big and bulky and their radiation output when active makes them a less than ideal choice. But oxygen as a reactant seems fine, though it seems like an expensive fuel source (given that the macross and colony ships would no doubt need large and continuous supplies of it).

[Vic Mancini]

As much as style and that ever present "cool" factor may be a part of Macross, I would stop short of calling FAST Packs needless. Space is huge, more so than most people can grasp. Interplanetary distances within the Sol system alone are vast.

Well, in that case are a couple of small shoulder FAST packs containing fuel, or reactant, or whatever, going to make a significant difference? Fuel consumption has never been a factor or a plot device in any Macross series that I can recall, (besides Zero which doesn't count for obvious reasons). I've never seen a Valk run out of gas and the pilot say, "Damn...if only I had some FAST packs, I could have made it to Jupiter!"

I'm sure they do contain Fuel/Reactant or have some kind of practical purpose behind them, but I think the practicality is more of an afterthought than the true purpose of why FAST packs are created for newer Valks... and that purpose is probably to look cool. It's the same reason why the SDF-1 transforms into a giant robot. It does so because it's cool. The practicality of needing to be in that mode to fire the main guns was most likely an afterthought to justify the necessity for putting a giant robot in the series. Hell, even the Zentradi themselves being 40ft tall was probably an afterthought to justify the necessity for building transforming fighter jets, when the actual reason they were created was probably no more significant than transforming fighter jets being cool.

I'm sure FAST packs have their purpose, all I'm trying to say is it's probably a mistake to over analyze what kind of internal gizmos/reactant they actually have or why they exploded in some scene where they were hit by gunfire. I've seen cars in movies explode from a single bullet to the gas tank, and computers in cartoons explode as if they were filled with dynamite...why? Because it looks cool. We might as well try to rationalize why there is sound in the vacuum of space. Sometimes there is no rational reason.

[Mr March]

Like I said, I would tend to agree that style and drama play a good part, but calling FAST Packs completely needless is stretching a good theory into implausibility. We don't really have enough information to judge how much fuel the valkyries use or need (or even the degree to which efficiency has improved over generations of variable fighters). The YF-19 fuel tanks in 2040 could actually provide more range than the large VF-1 fuel tanks in 2010. Comparing the VF-1 FAST Packs to the YF-19 FAST Packs in size alone is ignoring the design and function of each set. The VF-1 set added full boosters to increase velocity, while the YF-19 set does no such thing. This does not make the YF-19 set "less useful," it merely means the YF-19 packs serve a different function which may or may not be more or less relevant than previous generation FAST Packs. Ultimately, dismissing certain FAST Packs as "looking" useless pretty much is useless as any sort of definitive conclusion. I'd also keep in mind that Macross (for the most part) is set in the real robot genre and it clearly results in more consideration of technology than the average vapid science fiction show. Statistics continue to be publicized and nearly every new installment in the franchise has only added more description to the fictional technology.

[Vic Mancini]

Like I said, I would tend to agree that style and drama play a good part, but calling FAST Packs completely needless is stretching a good theory into implausibility. We don't really have enough information to judge how much fuel the valkyries use or need (or even the degree to which efficiency has improved over generations of variable fighters). The YF-19 fuel tanks in 2040 could actually provide more range than the large VF-1 fuel tanks in 2010. Comparing the VF-1 FAST Packs to the YF-19 FAST Packs in size alone is ignoring the design and function of each set. The VF-1 set added full boosters to increase velocity, while the YF-19 set does no such thing. This does not make the YF-19 set "less useful," it merely means the YF-19 packs serve a different function which may or may not be more or less relevant than previous generation FAST Packs. Ultimately, dismissing certain FAST Packs as "looking" useless pretty much is useless as any sort of definitive conclusion. I'd also keep in mind that Macross (for the most part) is set in the real robot genre and it clearly results in more consideration of technology than the average vapid science fiction show. Statistics continue to be publicized and nearly every new installment in the franchise has only added more description to the fictional technology.

Well I never said they were completely needless. I said that it's likely that the primary reason they were created was for the cool factor and because FPs have become a Macross tradition/novelty, and that any rational purpose for the FPs was probably an afterthought to justify their necessity. That doesn't mean they don't have a purpose, just that the purpose is probably a little more superficial than the VF-1s FPs for example.

The small size of the 19's and 21's FPs support this theory. They're so small and so conformal that there is no reason they couldn't be a part of the fighter's default design anyway. The fact that Isamu and Guld didn't jettison their FPs once their life and death struggle took to the atmosphere suggests that their added weight/drag isn't even enough to detract from the performance of the AVFs. Their Valks have limiters on them anyway and the limiters most likely adjust to allow the Valks to perform at maximum human thresholds with or without FPs. Kawamori could've easily designed the FPs right into the Valk and nobody would even notice. That could be an indication that the 19's FPs were created for the sake of giving it FAST packs and that the FPs are more arbitrary in nature than the VF-1s FPs.

And most importantly, you can't derive anything from seeing a FP explode, or the colour of the flame it gave off because there's not necessarily any logic behind that explosion. It might mean something, but it just as easily might not. It's probably just there for effect.

[Mr March]

Well I never said they were completely needless. I said that it's likely that the primary reason they were created was for the cool factor and because FPs have become a Macross tradition/novelty, and that any rational purpose for the FPs was probably an afterthought to justify their necessity. That doesn't mean they don't have a purpose, just that the purpose is probably a little more superficial than the VF-1s FPs for example.

Fair enough, but I completely disagree. There's nothing to suggest they are less or more useful, like I already said. Your mileage may vary. As for explosions, that's not my department in this thread

[Zinjo]

Fair enough, but I completely disagree. There's nothing to suggest they are less or more useful, like I already said. Your mileage may vary. As for explosions, that's not my department in this thread

The last "useful" FPs I recall were fitted to the VF-11 series and had a traditional purpose in combat operations. Additional sensors, firepower and speed during space combat engagements.

The rest of the FPs for the other fighters are purely for "coolness factor" IMHO. Similar to how Battle 7 didn't need to transform, but did because it was "cool"!

The only exception were the sound boosters, but speakers in space is another matter entirely...

Edited July 26, 2007 by Zinjo

[Graham]

The YF-19's and YF-21's FAST packs are definitely useful for the greater number of missles they allow the AVFs to carry. The YF-19 especially has a pretty limited missile load with just it's internal bays. The extra fuel in the shoulder packs will give longer range/persistence for space operations. Also, don't forget these were only prototype FAST Packs and perhaps not representative of the final production versions.

It's interesting to note that in the opening movie for the Playstation game Macross Digital Mission VF-X, the VF-19A is shown launching with traditional style back mounted booster type FAST packs. And of course the VF-19F/S in Macross 7 also use space/atmosperic capable back mounted booster type FAST packs.

Graham

[Shishigami]

Looook at whaatt I havee created!!! Muhahahaha

[Mr March]

The YF-19's and YF-21's FAST packs are definitely useful for the greater number of missles they allow the AVFs to carry. The YF-19 especially has a pretty limited missile load with just it's internal bays. The extra fuel in the shoulder packs will give longer range/persistence for space operations. Also, don't forget these were only prototype FAST Packs and perhaps not representative of the final production versions.

It's interesting to note that in the opening movie for the Playstation game Macross Digital Mission VF-X, the VF-19A is shown launching with traditional style back mounted booster type FAST packs. And of course the VF-19F/S in Macross 7 also use space/atmosperic capable back mounted booster type FAST packs.

Graham

As Duke Togo recently said, "egg-xactly"